In recent years, in order to achieve high reverse breakdown voltage and low loss in semiconductor devices as well as utilization thereof in a high temperature environment, silicon carbide (SiC) has begun to be adopted as a material for the semiconductor devices. Silicon carbide is a wide band gap semiconductor having a larger band gap than that of silicon (Si), which has been widely used as a material for semiconductor devices conventionally. Hence, the adoption of silicon carbide as the material for semiconductor devices will achieve high reverse breakdown voltage, reduced on resistance, and the like in the semiconductor devices. Further, when such semiconductor devices formed using silicon carbide as their material are utilized in a high temperature environment, the semiconductor devices are less deteriorated in properties as compared with semiconductor devices formed using silicon as their material, advantageously.
For example, it is reported that when SiC is adopted as a material for an insulated gate bipolar transistor (IGBT), which is a semiconductor device, a reverse breakdown voltage of 9 kV and an on resistance of 88 mΩcm2 under a gate voltage of 20 V are attained (see Qingchun Zhang et al., “9 kV 4H—SiC IGBTs with 88 mΩcm2 of Rdiff,on”, Materials Science Forum, 2007, Vols. 556-557, p. 771-774 (Non-Patent Document 1)).